Combining snmp sensors

Configuration
1

I have 2 snmp sensors set up to read out the modem state of my LTE router (easy 1 or 0) and to read out the cell technology (2g, 3g, LTE).
I already have a template set up (no earthly idea how I figured it out though, I am still working on it) to translate the cell tech numbers to readable format as so:

        friendly_name: "Cell Technology"
        value_template: >-
          {% set mapper =  {
              '0' : 'Disconnected',
              '1' : 'Disconnected',
              '2' : '2 GPRS',
              '3' : '3 Edge',
              '4' : '4 UMTS',
              '5' : 'HSDPA+',
              '6' : '6 3G HSDPA',
              '7' : '7 3G HSUPA',
              '8' : 'LTE' } %}
          {% set state =  states.sensor.wr11_wan_tech.state %}
          {{ mapper[state] if state in mapper else 'Disconnected' }}
        icon_template: >-
          {% set mapper =  {
              '0' : 'mdi:signal-off',
              '1' : 'mdi:signal-off',
              '2' : '2 GPRS',
              '3' : '3 Edge',
              '4' : '4 UMTS',
              '5' : 'HSDPA+',
              '6' : '6 3G HSDPA',
              '7' : '7 3G HSUPA',
              '8' : 'mdi:signal-cellular-3' } %}
          {% set state =  states.sensor.wr11_wan_tech.state %}
          {{ mapper[state] if state in mapper else 'mdi:signal-off' }}

But whenever the modem disconnects, the last cell tech persists so I’d love to find out how to set up a template that shows the cell tech text if the modem is connected and displays “Disconnected” when the modem is disconnected.
As a bonus I’d love it if the icons could be yellow when connected and grey when the modem is disconnected.
Many thanks for the help!

2

You could use an availability trigger. While that will report “unavailable” rather than “disconnected”, it’s a more typical approach.

3

With “modem disconnects” I am pointing to the internal modem of the device. The device itself stays on at all times. It is an snmp value returning 0 or 1 accordingly.

I am living with older co-inhabitants and they get confused when things are named improperly so I need to name things properly if I want them to use this at all.